Dublin drains Mud Pond while deliberating dam’s future

  • The Mud Pond dam in Dublin was dewatered earlier this year. The pond's previous waterline is now visible on exposed rock, concrete, and silt. Staff photo by Abbe Hamilton

  • The Mud Pond dam in Dublin was dewatered earlier this year. The pond's previous waterline is now visible on exposed rock, concrete, and silt. Staff photo by Abbe Hamilton—

  • The Mud Pond dam in Dublin was dewatered earlier this year. The pond's previous waterline is now visible on exposed rock, concrete, and silt. Staff photo by Abbe Hamilton

  • The Mud Pond dam in Dublin was dewatered earlier this year. The pond's previous waterline is now visible on exposed rock, concrete, and silt. Staff photo by Abbe Hamilton—

  • The Mud Pond dam in Dublin was dewatered earlier this year. The pond's previous waterline is now visible on exposed rock, concrete, and silt. Staff photo by Abbe Hamilton—

  • The Mud Pond dam in Dublin was dewatered earlier this year. The pond's previous waterline is now visible on exposed rock, concrete, and silt. Staff photo by Abbe Hamilton—

  • The Mud Pond dam in Dublin was dewatered earlier this year. The pond's previous waterline is now visible on exposed rock, concrete, and silt. Staff photo by Abbe Hamilton—

  • Building the dam for Dublin Electric, circa 1899. Photo from Dublin archives, courtesy of Charles F. Appleton Collection. Courtesy image from Dublin Historical Society—

  • Horses deliver the last load of penstock sections from the East Harrisville railroad station to Stanley Brook in 1907. Courtesy image from Dublin Historical Society—

  • The dam in winter, around 1899. From the Charles F. Appleton collection. Courtesy image from Dublin Historical Society—

Monadnock Ledger-Transcript
Published: 6/22/2020 4:20:49 PM

The Town of Dublin has dewatered Mud Pond after a 2018 Department of Environmental Services inspection deemed its dam “in extremely poor condition,” with some deficiencies that could lead to a premature failure. The dam, built by the Dublin Electric Company in 1917, is 238 feet long, 17.5 feet high, and now owned by the town. “The problem is the dam’s concrete... is deteriorating,” Select Board Chair Walter Snitko said. “The question is what we do with it.” Even just a study of options is likely to cost in the tens of thousands, Snitko said, and a repair or replacement is somewhere in the six figures, he said.

Travelers on Route 101 pass over Mud Pond, which takes up a substantial wetlands area in the headwaters of Stanley Brook. The dam itself  is on the north side of the road. Its water flows into the Edward MacDowell reservoir. Due to the dam’s location, it was classified as a non-menace structure and a failure would not likely result in loss of life or property, DES dam safety engineer Charlie Krautmann said, and it’s in the dam owner’s authority to change the water level, reconstruct the dam, or let it fall apart over time. The town opted to let all the water out of the dam last fall after speaking to the MacDowell dam operators, Snitko said, so the structure is under less stress as the town looks into options.

There’s now a large stream running where the water used to pond, according to Peter Naylor, who lives on an adjacent property with his father. “The banks are so muddy you can’t really get to the water or launch a boat without putting on muck boots,” he said. He and his father have historically enjoyed fishing the pond. On the bright side, the low water could make it much easier to catch favorites like horned pout, he said. Naylor said he would like to see the town maintain a consistent water level, whether that means refilling the dam or letting the banks dry up for good.

The first dam on site was built before 1899, Dublin Historical Society archivist Lisa Foote said, which was when the Dublin Electric Company rebuilt an existing dam with stone and wood to provide electricity for lighting in Dublin. There’s been industry on the dam’s site since the late 1700s, she said, when a James Houghton operated a grist and saw mill on the site. It was later converted to a shoe peg mill, which made pegs to attach shoe soles to uppers. The exclusively wood-based industries in town make it unlikely that the sediments impounded behind the dam would be contaminated with anything hazardous, she said.

DES oversees any dam with more than a four foot head, and private landowners can have a lien attached to their property if the DES repairs an at-risk structure, Wilton Select Board member Matt Fish said.

“It costs sometimes the same amount of money to take a dam out than to fix it,” Fish said. About ten years ago, the Old Reservoir dam above Garwin Falls was determined a high risk structure, and the town agreed to leave the flood gates open and keep the passage clear to comply with DES recommendations. When the New Reservoir dam was also classified as high risk recently, the town funded a study which determined they could modify the structure rather than totally replace it, Fish said.

The Dublin Conservation Commission estimated that an engineering study for the Mud Pond dam would cost about $15,800 when they received a quote in 2018, chair Jay Schechter said. It’s not feasible to return the dam to hydroelectric generation, he said. Any final decision would come after public hearings, Snitko said, and voters would need to approve funds spent at Town Meeting.

Of the state’s 4800 dams, most are more than 150 years old and most can increase the risk of flooding rather than control floods, DES stormwater coordinator Deborah Loiselle said. Loiselle served as dam removal and restoration coordinator for 10 years. “There are like 2,000 dams that don’t do a single thing in New Hampshire,” Souhegan Watershed Association president George May said. “Some people who own them don’t even know that they do.”

Conversations about dam removals typically make stakeholders either extremely happy or extremely upset and angry, Loiselle said. If a stakeholder group feels strongly about keeping the dam, it’s possible to transfer ownership to them, although it comes with the liability and cost of upkeep, she said.

Although stakeholders are typically mortified by the sight of a dam right when it’s been drawn down, “at the end of the summer, or the fall, or next spring, you’re gonna see something very different,” Loiselle said, as mud flats green up, the stream scours sediment away and new fish species populate the stream. The situation is a good opportunity to study what could happen if the dam were partially or fully removed, she said, since simply opening the flood gate is likely not enough to return the stream to its natural flow.

“There’s a lot of environmental value to removing a dam and bringing things back to its natural processes,” Loiselle said. Dams can contribute to poor water quality, interrupt fish passage, and build up sediment that would otherwise flow downstream. Funding sources are typically available to offset the cost of dam removal, she said, some specifically for municipalities. More funds are available if the restoration could help repopulate a target species, or if the pond’s water quality had been impaired, she said.

Rebuilding the impoundment would constitute another big shock to the ecosystem now that it’s been dewatered, DES limnologist Amy Smagula said. “Certain organisms might not be able to keep up,” she said. “It takes a while for it to start acting like a lake again,” she said.




Monadnock Ledger-Transcript

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